Plum tree named `Compact Friar`

ABSTRACT

A plum tree named Compact Friar similar to Friar plum, of which it is a mutation, but distinguished by dwarf size of the tree.

ORIGIN AND REPRODUCTION

This petition is for a new cultivar of Japanese plum (Prunus salicina).As research partner of a tree breeding enterprise, I directed anexperimental program to breed new cultivars of stone fruits by treatingbudwood with cobalt 60 Picowave radiation in dosages ranging from 1,500rads to 18,000 rads to induce mutations and then budding the treatedbuds onto Nemaguard peach (unpatented) rootstock in an experimental plotin San Joaquin county. One of the trees resulting from such budding,being a mutation of Friar plum (unpatented) was observed by me uponmaturity to have novel characteristics. It was around half the size ofregular Friar, offering a potential for high density plantings andreduced costs for cultivation and harvesting. At my direction, buds fromit were then further budded on other Nemaguard rootstock in the sameexperimental plot. These later asexual reproductions have been true tothe tree from which the buds were taken. I have personally alsoreproduced this new cultivar by budding onto peaches and plums in myfacilities in Alameda County, Calif.

SUMMARY OF THE INVENTION

This new cultivar of plum tree is a productive regular bearer ofyellowish amber fleshed, purplish black skinned, oblate fruit ripeningin late July. It is similar to Friar, except that this tree isgenetically dwarf in size. By its dwarf tree size and ripening of fruitin late July, it is distinguishable from Majestic M plum (U.S. PlantPat. No. 6,975), also a mutation of Friar, which has a regular size treeand fruit ripening in late October.

PHOTOGRAPHS AND DETAILED DESCRIPTION

The accompanying photographs show two trees of this new cultivar intheir fourth summer, a twig with detached leaves, and fruits both wholeand divided in half, with the stone in one half.

Following is a botanical description of this new variety with fruit infirm condition based on Jul. 17, 1990 observation of two specimen treesin San Joaquin County, Calif. Color names and plate numbers are byreference to Inter-Society Color Council--National Bureau of StandardsCentroid Color Charts, except where common color names are used.

Tree: Dwarf size (5 feet in 4th summer), dense, medium vigor, regularbearer, precocious, highly productive (around 50 fruits in 4th summer)form upright spreading to round with wide angle crotches on branches.Friar, in comparison, is twice as tall, less dense, more upright, withnarrower angled crotches. Third generation trees of the new varietybudded on myrobolan root appeared less dwarfy in the first year thanthose budded on Nemaguard.

Trunk: 11/2 inches in diameter, normal texture of plum bark, averagenumber of white lenticels.

Branches: 5/8 to 3/4 inches in diameter, brown color, normal plum barktexture, shorter than normal internodes. A 1992 sample of internodes inAlameda County averaged 2.2 cm compared to 2.75 cm for Friar.

Leaves:

Size.--8 cm. long, 3 cm. wide. 1992 sample of trees in Alameda Countyaveraged 9.5 cm long, 3.5 cm wide, very similar to Friar.

Shape.--Oblanceolate slightly cupped, base obtuse (some inequilateral),apex acuminate.

Color.--Top side moderate olive green (125), bottom side grayish yellowgreen (122).

Margin.--Serrate.

Venation.--Arcuate, some midribs with pinkish hue at basal end.

Glands.--Generally none; occasionally one on each side of petiole nearleaf base, globose in form. 1992 sample of trees in Alameda Countyshowed average of 2 glands per leaf, with a range of 0 to 3, same asFriar.

Petiole.--Average length 1.7 cm., mostly dark greenish yellow (103) butsome pinkish.

Stipules.--Absent.

Flowers (as observed February 1991 in Alameda County, Calif.):

Buds.--Medium size, conical shape, non-pubescent.

Flowers.--Generally similar to Friar, midseason blooming, one to sixflowers per node, each flower containing five white, medium-size petals,light yellow stamens, and yellow pistil.

Pollination.--Self-incompatible like Friar; a suitable pollinator isrequired.

Fruit: Large size averaging 4.1×4.6×4.3 cm (axial, cheek to cheek, andsuture diameters); form moderately oblate; cavity 1.5×0.6 cm.; baseround; apex round to truncate, some slightly depressed; suture indentedby unmarked; stem averaging 0.7 cm. long, medium thickness. 1991observations in Alameda County showed this to be similar to Friar insize, shape, uniformity and time of ripening (3rd week of July).

Skin: Thin to medium, glabrous; vivid dark purple (225) when less ripeto purplish black (235) when more ripe; no cracking; covered by bluishgray (191) bloom; peels easily but some flesh adheres to skin.

Flesh: Brilliant orange yellow (67); mild sweet flavor; mild aroma;juicy, smooth, melting; ripens evenly; eating quality very good.

Stone: Length 1.8 cm., width 1.2 cm., thickness 0.9 cm., substantiallyfreestone, light yellowish brown color (76) when dry, obovate form, baseobtuse, apex accuminate, surface rough and wrinkly, one edge groovedwith the other ridged, few splits. In comparison, a 1990 sample of Friarstones were of the same size, but less uniform in shape, approximately75% being round and only 25% oval to obovate. Fertility of stones hasnot been tested.

Use: Home orchards or special application in commercial orchards.

Keeping quality: Good.

Shipping quality: Unknown.

The plum tree and its fruit herein described may vary in slight detaildue to difference in climate, soil, pruning, fertilization or otherpractices or growing conditions. The present description is of thevariety as grown in an experimental plot is San Joaquin County, Calif.

I claim:
 1. A new and distinct variety of plum tree, substantially asillustrated and described, identified by the characteristics enumeratedabove, and characterized particularly as to novelty in comparison toother plum trees by the genetically dwarf size of tree, but otherwisesimilar to the Friar plum tree from which it mutated.